def get_breadcrumb(category):    """    传入三级类别模型对象    """    # 定义字典用来包装面包屑数据    breadcrumb = {}    breadcrumb['cat3'] = category    breadcrumb['cat2'] = category.parent    cat1 = category.parent.parent    cat1.url = cat1.goodschannel_set.all()[0].url    breadcrumb['cat1'] = cat1    return breadcrumb